Capillary Force Induced Elastic Deformation on ZnS Nanobeams

2011 ◽  
Author(s):  
Xinnan Wang ◽  
Xiaodong Li
Keyword(s):  
Electron Microscope ◽  
Surface Energy ◽  
Total Energy ◽  
Elastic Deformation ◽  
Capillary Force ◽  
Elastic Beam ◽  
Small Strain ◽  
Beam Deflection ◽  
Atomic Force ◽  
Transmission Electron

In this study, synthesized Wurtzite-structured ZnS nanobelts was investigated using high resolution transmission electron microscope, atomic force microscope, and scanning electron microscope for structural and morphology analyses. Results show that ZnS nanobelts are tens of microns in length, mostly ∼40×50 nm2 in width and thickness. The nanobelts grow along direction [001] and are dislocation free. The distance spacing for (001) plane is 3.19A˚. The capillary force was found strong enough to deform the ZnS nanobeam down to the substrate. Theoretical analysis on small strain elastic deformation was conducted. It was found that as the maximum beam deflection increases, beam elastic energy increases; in the meantime, the surface energy decreases. The net increase in elastic beam energy is less than the net decrease in the surface energy, resulting in total energy decrease. In addition, as the volume of liquid increases, for a certain maximum beam deflection, the total energy increases, this is result of the increase of the surface energy. Furthermore, for a specific nanobeam to be deflected to the underlying surface, the amount of liquid can be calculated.

Computer simulations of interactions between ultrafine alumina particles produced by an arc discharge

1997 ◽  
Vol 12 (1) ◽  
pp. 235-243 ◽  
Author(s):  
M. H. Teng ◽  
L. D. Marks ◽  
D. L. Johnson
Keyword(s):  
Electron Microscope ◽  
Surface Energy ◽  
Transmission Electron Microscope ◽  
Arc Discharge ◽  
Total Surface Energy ◽  
Transmission Electron ◽  
Initial Stage ◽  
Alumina Particles ◽  
Rearrangement Process ◽  
Particle Chains

We wrote two computer programs, 3D and BUMP, to interpret transmission electron microscope (TEM) micrographs made during a study of the initial stage sintering of ultrafine alumina particles (UFP's, 20–50 nm in diameter). The first simulated the 3D geometric relationships of particles, from which we concluded that surface diffusion was the predominant sintering mechanism because no shrinkage occurred. BUMP simulated random contact of two particles and showed that the particle chains that formed before sintering were not formed purely by chance. Instead the particles experienced a rearrangement process (rotation and sliding) which reduced the total surface energy.

In situ transmission electron microscope measurements of solid Al-solid Pb and solid Al-liquid Pb surface-energy anisotropy in rapidly solidified Al-5% Pb (by mass)

1987 ◽  
Vol 414 (1847) ◽  
pp. 499-507 ◽  
Keyword(s):  
Electron Microscope ◽  
Melting Point ◽  
Surface Energy ◽  
Transmission Electron Microscope ◽  
Room Temperature ◽  
Transmission Electron ◽  
Increasing Temperature ◽  
Rapidly Solidified ◽  
Al Matrix

Alloys of Al-5% Pb and Al-5% Pb-0.5% Si (by mass) have been manufactured by rapid solidification and then examined by transmission electron microscopy. The rapidly solidified alloy microstructures consist of 5-60 nm Pb particles embedded in an Al matrix. The Pb particles have a cube-cube orientation relation with the Al matrix, and are cub-octahedral in shape, bounded by {100} Al, Pb and {111} Al, Pb facets. The equilibrium Pb particle shape and therefore the anisotropy of solid Al-solid Pb and solid Al-liquid Pb surface energies have been monitored by in situ heating in the transmission electron microscope over the temperature range between room temperature and 550°C. The ani­sotropy of solid Al-solid Pb surface energy is constant between room temperature and the Pb melting point, with a {100} Al, Pb surface energy about 14% greater than the {111} Al, Pb surface energy, in good agreement with geometric near-neighbour bond energy calculations. The {100} AI, Pb facet disappears when the Pb particles melt, and the anisotropy of solid Al-liquid Pb surface energy decreases gradually with increasing temperature above the Pb melting point, until the Pb particles become spherical at about 550°C.

Examination of Atomic (Scanning) Force Microscopy Probe Tips with the Transmission Electron Microscope

1997 ◽  
Vol 3 (3) ◽  
pp. 203-213 ◽  
Author(s):  
J.A. DeRose ◽  
J.-P. Revel
Keyword(s):  
Atomic Force Microscopy ◽  
Electron Microscope ◽  
High Resolution ◽  
Transmission Electron Microscope ◽  
Scanning Force Microscopy ◽  
Image Deconvolution ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Scanning Force

Abstract: We have developed a method for the examination of atomic force microscopy (scanning force microscopy) tips using a high-resolution transmission electron microscope (TEM). The tips can be imaged in a nondestructive way, enabling one to observe the shape of an atomic force microscope probe in the vicinity of the apex with high resolution. We have obtained images of atomic force microscopy probes with a resolution on the order of 1 nm. The tips can be imaged repeatedly, so one can examine tips before and after use. We have found that the tip can become blunted with use, the rate of wear depending upon the sample and tip materials and the scanning conditions. We have also found that the tips easily accrue contamination. We have studied both commercially produced tips, as well as tips grown by electron beam deposition. Direct imaging in the TEM should prove useful for image deconvolution methods because one does not have to make any assumptions concerning the general shape of the tip profile.

Silica Encapsulated CdS Tabular Nanocomposites via a Template Directed Agglomeration Mechanism

2008 ◽  
Vol 8 (11) ◽  
pp. 5878-5886 ◽  
Author(s):  
Jun Wang ◽  
Stephen J. Sollenberger ◽  
Ying Yuan ◽  
Timothy J. Yosenick ◽  
James H. Adair
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Coating Layer ◽  
Layer Growth ◽  
Cds Nanoparticles ◽  
Atomic Force ◽  
Transmission Electron ◽  
Potential Applications ◽  
Hydrolysis Of

Silica coated CdS tabular nanocomposites were synthesized through precipitation of CdS nanoparticles in octylamine/water bilayer system followed by in situ hydrolysis of tetraethoxylsilicate (TEOS) precursor. Face diameter of the nanoplatelets was in the range of 50∼250 nm with a variable thickness (3 to 25 nm) dictated by octylamine content or R ratio ([water]/[octylamine]). A uniform SiO2 outer shell of about 15 nm was observed regardless of the size of the high aspect ratio CdS nanoplatelets, which appeared to be agglomerated primarily owing to the confined bilayer template. Morphology and microstructure of the CdS/SiO2 tabular nanocomposites were characterized using atomic force microscope (AFM) and high resolution transmission electron microscope (HRTEM). A noticeable enhancement in absorbance for the UV-vis spectra was observed due to the SiO2 coating layer. Growth mechanism of nanocomposite platelets and potential applications associated with this anisotropic nanocomposite are discussed.

Wear Characteristics of Atomic Force Microscope Probe Tips

2005 ◽  
Author(s):  
Koo-Hyun Chung ◽  
Dae-Eun Kim
Keyword(s):  
Electron Microscope ◽  
Atomic Force Microscope ◽  
Atomic Force Microscope Probe ◽  
Wear Characteristics ◽  
Atomic Force ◽  
Transmission Electron ◽  
Afm Probe ◽  
Silicon Silicon ◽  
Microscope Probe ◽  
Scanning Electron

In the field of nanotechnology, Atomic Force Microscope (AFM) which is based on the interactions between an extremely sharp probe tip and specimen, has been widely utilized. In the AFM and AFM-based applications, the probe tip wear problem should be carefully considered. In this work, the wear characteristics of silicon, silicon nitride, and diamond coated probe tip under light loads were investigated. In order to identify the structure of the AFM probe tips as well as the nature of wear, High-Resolution Transmission Electron Microscope (HRTEM) and Field Emission Scanning Electron Microscope (FESEM) analyses were utilized. Using the Archard’s wear equation, the degree of the probe tip wear was quantitatively assessed. Based on the experimental results and analysis, the plausible wear mechanisms of the AFM probe tips were proposed in an effort to understand the nano-scale wear.

Voltammetric detection of nitroaromatic compounds using carbon-nanomaterials-based electrodes

2011 ◽  
Vol 89 (1) ◽  
pp. 8-12 ◽  
Author(s):  
Hong-Xia Zhang ◽  
Jun-Hong Zhang
Keyword(s):  
Electron Microscope ◽  
Glassy Carbon ◽  
Carbon Nanomaterials ◽  
Nitroaromatic Compounds ◽  
Electrochemical Technique ◽  
Lower Sensitivity ◽  
Multi Wall Carbon Nanotubes ◽  
Atomic Force ◽  
Transmission Electron ◽  
Voltammetric Detection

The morphology of glassy carbon surfaces was investigated by the atomic force microscope (AFM) method. Multi-wall carbon nanotubes (MWCNTs) were purified and investigated with a scanning electron microscope (SEM) and a transmission electron microscope (TEM). An electrochemical technique based on the glassy carbon electrode (GCE) or MWCNT-modified GCEs was used for the detection of nitroaromatic compounds (NACs), namely 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitrobenzene (TNB), 2,4-dinitrotoluene (2,4-DNT), and 1,3-dinitrobenzene (1,3-DNB). MWCNT-modified GCEs were more sensitive than GCEs to TNB, 2,4-DNT, and 1,3-DNB, with the detection limit down to ppb level, whereas the modified GCEs showed lower sensitivity to TNT. In varying degrees, the accumulation of nitro compounds can be promoted by MWCNT-modified GCEs in the detection process, a property which can be attributed to the large surface area and graphene-sheet structure of MWCNTs.

The Self-assembled Deposition on the Surface of Mono-crystalline Silicon Induced by High-Current Pulsed Electron Beam

2017 ◽  
Vol 36 (6) ◽  
pp. 593-597
Author(s):  
Zhang Conglin ◽  
Guan Qingfeng ◽  
Chen Jie ◽  
Yan Pengcheng ◽  
Lv Peng
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Crystalline Silicon ◽  
High Current ◽  
Pulsed Electron Beam ◽  
Atomic Force ◽  
Transmission Electron ◽  
Si Nanoparticles ◽  
Surface Microstructures ◽  
Pulsed Irradiation

AbstractHigh-current pulsed electron beam (HCPEB) technique was applied to irradiate the surface of mono-crystalline silicon wafers. Surface microstructures of the irradiated surface were investigated in detail by atomic force microscope (AFM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The experimental results show that HCPEB irradiation with energy density 4 J/cm2 caused evaporation of the irradiated surface. Subsequently, the evaporation Si-droplets was deposited to form Si-nanoparticles on the surface. Meanwhile, the structures of intensive plastic deformation were also introduced within the irradiated surface layer. The dislocation configurations with rectangular and approximate hexagonal network were formed on the surface of Si wafer after 5-pulsed irradiation. The periodic self-deposited structures appear to be related to the configuration of regular dislocations arrays, which were favorable locations for the deposited Si-nanoparticles.

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